forked from GithubBackups/healthchecks
65 lines
2.0 KiB
Markdown
65 lines
2.0 KiB
Markdown
# Attaching Logs
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SITE_NAME ping endpoints accept HTTP HEAD, GET and POST request methods.
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When using HTTP POST, **you can include arbitrary payload in the request body**.
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If the request body looks like a UTF-8 string, SITE_NAME will log the
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first 10 kilobytes (10 000 bytes) of the request body, so you can inspect it later.
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## Logging Command Output
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In this example, we run `certbot renew`, capture its output (both the stdout
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and stderr streams), and submit the captured output to SITE_NAME:
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```bash
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#!/bin/sh
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m=$(/usr/bin/certbot renew 2>&1)
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curl -fsS -m 10 --retry 5 --data-raw "$m" PING_URL
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```
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## In Combination with the `/fail` and `/{exit-status}` Endpoints
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We can extend the previous example and signal either success or failure
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depending on the exit code:
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```bash
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#!/bin/sh
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m=$(/usr/bin/certbot renew 2>&1)
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curl -fsS -m 10 --retry 5 --data-raw "$m" PING_URL/$?
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```
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## Using Runitor
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[Runitor](https://github.com/bdd/runitor) is a third party utility that runs the
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supplied command, captures its output and and reports to SITE_NAME.
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It also measures the execution time, and retries HTTP requests on transient errors.
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Best of all, the syntax is simple and clean:
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```bash
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runitor -uuid your-uuid-here -- /usr/bin/certbot renew
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```
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## Handling More Than 10KB of Logs
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While SITE_NAME can store a small amount of logs in a pinch, it is not specifically
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designed for that. If you run into the issue of logs getting cut off, consider
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the following options:
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* See if the logs can be made less verbose. For example, if you have a batch job
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that outputs a line of text per item processed, perhaps it can output a short
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summary with the totals instead.
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* If the important content is usually at the end, submit the **last 10KB** instead
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of the first. Here is an example that submits the last 10KB of `dmesg` output:
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```bash
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#!/bin/sh
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m=$(dmesg | tail --bytes=10000)
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curl -fsS -m 10 --retry 5 --data-raw "$m" PING_URL
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```
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* Finally, if for your use case it is critical to capture the entire log output,
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consider using a dedicated log aggregation service for capturing the logs.
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